This invention relates to a linear driving mechanism using a rotary means, more particularly to a novel improvement for obtaining a very compact, highly reliable construction for a linear driving mechanism.
Conventionally, there have been many kinds of linear driving mechanisms having said rotary means. FIGS. 1 and 2 are showing a representative construction in the prior art.
In the constructions shown in FIGS. 1 and 2, a pair of bar shaped guide members 2 and 3 are fixed across a U-shaped frame 1. Further, a guide axis 5 having a threaded portion 4 is rotatably mounted between said guide members 2 and 3.
A nut member 6 is thredably engaged with the outer surface of said guide axis 5 through said threaded portion 4, a movable table member 7 being unitarity mounted to said nut member 6.
One end portion 5a of said guide axis 5 protrudes through an outer portion of said frame 1 through a part of said frame 1, said one end portion 5a of said guide axis 5 being connected with a joint member 8 that is mounted to said frame 1. A solenoid motor 9 is connected with said joint member 8 for rotatably moving said guide axis 5.
In said construction above, power from a power source, not shown, is supplied to said solenoid motor 9 via a power supply lead wire 9a, which then drives said guide axis 5 to rotate through said joint member 8, said movable table member 7 being reciprocally moved in the direction of an arrow A via said nut member 6.
However, in the above noted conventional construction, since said guide axis 5 is rotated by said joint member 8 and said solenoid motor 9 which are mounted to the outer portion of said frame 1 as means for reciprocally moving said movable table member 7, it is necessary to provide suitable space for mounting said joint member 8 and said solenoid motor 9 to said frame 1 as a linear driving mechanism.
Furthermore, since it is necessary to provide said joint member for connecting said guide axis 5 and said solenoid motor 9, there is a cost-problem over and above said space problem.
Therefore, this can not meet the requirements of users calling for linear driving mechanism as compact as possible and such a construction is the biggest hurdle to constructing small and compact automatic mechanisms such as computer drafting machines and robot mechanisms which use said linear driving mechanism.